Rattling vibration through steering

[keithlard]

I'm getting a sort of graunching (good technical term!) rattling noise and vibration coming through the steering when accelerating through about 2000 RPM. It only seems to happen under acceleration, and it goes away quite quickly as the engine speeds up. It sounds a little as though there is a bag of bolts in the engine bay.

I'm guessing something is a little bit loose and resonating at this frequency - any guesses? Exhaust? I did have an unfortunate scrape over a speed bump

[rip]

I had a shaking at a certain speed under acceleration which eventually got as bad as between 50-70 mph regardless of gear. When I eased off the power, the vibration ceased. I heard no noises other than rattles caused by the vibration.

It turned out to be a worn driveshaft joint. (Exactly as Enright diagnosed when I first described it to him ).

If this sounds like your fault, get it sorted sooner rather than later.
By the time I got mine fixed, it had weakened a bolt which secures one of the shafts. This caused a lesser vibration & later it inevitably failed, leaving me stranded without drive or gearbox oil.
Lotus had driveshafts on sale for around £100 ea.

[keithlard]

It doesn't sound exactly like it, especially as it seems to be sensitive to engine speed rather than road speed. However I will get my mechanic to have a look just in case it is something nasty like the driveshaft. Thanks!

[Monty]

Make sure the wheel bolts haven`t come loose, next step is to check for play in wheel bearings, driveshafts and to check all the bolts on the suspension haven`t come loose.

[rip]

If it's definitely related to engine speed, then it sounds like the problem is the other side of the transmission from the driveshafts.
Just trying to think how that would affect steering...Is there anything connected to the engine which runs near enough to the steering rack to be knocking it?

[mnemonix]

If it's definitely related to engine speed, then it sounds like the problem is the other side of the transmission from the driveshafts.
Just trying to think how that would affect steering...Is there anything connected to the engine which runs near enough to the steering rack to be knocking it?

The exhaust pipe if you have a larger bore system. Gerald at GST commented on this phenomenon to me once.

Chris.

[keithlard]

Funnily enough it was exactly what I thought it was - the exhaust had got knocked slightly out of place when grounding over a speed bump, and was touching something.

Driving an Elan, you soon develop a phobia of speed bumps, rough roads and driveway ramps!